Watch-crown holder



(No Model.)

, N. T. MILLS.

WATCH GROWN HOLDER.

No. 467,294. Patented Jan. 19, 1892.

UNITED STATES PATENT OFFICE.

NORMAN T. MILLS, OF BOSTON, MASSACHUSETTS.

WATCH-CROWN HOLDER.

SPECIFICATION forming part of Letters Patent No. 467,294, dated January 19, 1892.

Application filed 18, June 1891.

To all whom it may concern.-

Be known that I, NORMAN T. MILLS, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Vtatch- Crown Holders, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention has for its object to construct a watch-crown holder adapted to be held in a lathe-chuck.

In accordance with this invention an externally-screw-threaded block having a cylindrical stem adapted to be held byanysuitable chuck is bored out axially to receive a longitudinally adjustable back rest, preferably provided with aeushion. A hemispherical shell having an annular flange at one end and an opening at the other end is provided, which is held in position by an externallyscrew-threaded flanged coupling-ring adapted to be turned 011 said externally-screwthreaded block, the flange of said couplingring engaging the flange on the hemispherical shell.

Figure 1 shows a horizontal section of a watch-crown holder embodying this invention; Fig. 2, details to be referred to.

The cylindrical block b, externally-screwthreaded, as shown in Fig. 1, has formed integral with or attached toit a cylindrical stem 1) of lesser diameter than the block, said stem being adapted to fit a split chuck, as c, of a lathe. The block Z2 and its stem are bored axially to receive a back-rest, which is herein shown as a cylindrical stem d, having a conc'aved head cl, preferably provided with a yielding cushion or covering 61 The stem 61 is provided with a circumferential groove (Z and a set-screw d is screwed into the stem 1), entering the recess d and adapted to bear against the stem d and hold the back-rest in adjusted position. The rear end of the center bore or hole in the stem 2) is internallyscrew-threaded to receive an adj usting-screw 01 which bears against the rear end of the stem 01 of the back-rest to provide for longitudinal adjustment thereof.

A hemispherical shell e, having at one end an annular flange e and at the other end an.

Serial No. 396,710- (No model.)

opening e is provided, and a coupling-ring f, internally-screw-threaded to be turned on the externally-screw-threaded block b and provided with a flange f, which engages the flange e of the shell e, is also provided which co-operates with the back-rest to hold a watchcrown, as g, firmly in position.

As watch-crowns vary in size I have provided shells, as 6, made externally alike but internally of different dimensions for different-sized crowns, as shown in Fig. 2.

To place the crown in position to be operated upon, the crown is placed in the hernispherical shell, which is dropped into the internallyscrew threaded flanged couplingringf, and the latter is then turned upon the externally-screw-threaded block b until the crown bears firmlyagainst the cushioned back rest.

I claim-- 1. In a watch-crown holder, the externallyscrew-threaded block I), having a cylindrical stem, the longitudinally-adjustable back-rest provided with a concave head, and a yielding cushion thereon, combined with the hollow hemispherical shell provided with an annular flange e and an opening 6 and the internally-screw-threaded flanged couplingring adapted 'to be turned on said screwthreaded block, the flange on said ring engaging the flange on the shell, the head and shell holding the watch-crown between them, substantially as described.

2. In a watcl1crown holder, the externallyscrew-threaded block supporting a back-rest having a concaved work-supporting head and means for positively adjusting said rest, combined with a hollow hemispherical shell having an annular flange e and a hole c and the internally-screw-threaded flanged coupling-ring adapted to be turned on said block, the flange of said ring engaging the flange of the shell, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

NORMAN T. MILLS.

Witnesses:

BERNICE J. NOYES, EMMA J. BENNETT. 

